Alkylmethylsilanes

ABSTRACT

ALKYLMETHYLSILANES AND ALKYLDIMETHYLSILANES HAVING ALKYL GROUPS OF 12 TO 45 CARBON ATOMS ARE DISCLOSED. THE ALKYIMETHYLSILANES ARE USEFUL AS EVAPORATION RETARDANTS.

United States Patent 3,567,754 ALKYLMETHYLSILANES Richard W. Alsgaard, Midland, Mich., assignor to Dow Corning Corporation, Midland, Mich. No Drawing. Filed Aug. 15, 1968, Ser. No. 752,778 Int. Cl. C07f 7/08 US. Cl. 260448.2 4 Claims ABSTRACT OF THE DISCLOSURE Alkylmethylsilanes and alkyldimethylsilanes having alkyl groups of 12 to 45 carbon atoms are disclosed. The alkylmethylsilanes are useful as evaporation retardants.

This invention relates to alkylmethylsilanes.

An object of the present invention is to provide a new class of alkylmethylsilanes which are useful as evaporation retardants.

The present invention relates to an alkylmethylsilane of the formula (CuH2n+l SiH(3-x) in which n is an integer of from 12 to 45 inclusive and x is an integer of from 1 to 2 inclusive.

The alkylmethylsilanes can best be prepared by reacting an a-olefin with H(CH )SiClor H(CH SiCl in the presence of a platinum catalyst, such as chloroplatinic acid. The resulting product has a formula 3 (CHM (C H2 )SiCl2 or (CnH2u I-I) The chlorosilanes are then mixed with lithium aluminum hydride to produce the corresponding hydrides of the formulae (3H3 (OHM (OnHznn) 112 and n n+l) The u-olefin can be any alkene which has a carboncarbon double bond at a terminal carbon atom and which has 12 to 45 carbon atoms. The a-olefins can be either straight chained or branched and include, for example, a-dodecene, a-pentadecene, a-tridecene, u-octadecene, wtetradecene, CH2=CH(CH2)17CH3,

CH CH (CH CH 2= CH 2) zs s 2= 2)1o al2,

CH CH (CH CH 2= 2)19 a,

and CH =CH(CH CH(CH The alkylmethylsilanes of the present invention can include, for example,

1 CH (C H2) 15SiH2, CH3 (CH2) HSiHi The alkylmethylsilanes of the present invention are particularly useful as evaporation retardants. The alkylmethylsilanes are applied to the surface of an aqueous body which is exposer to a gaseous atmosphere. The amount of alkylmethylsilane applied is determined by several factors, such as, temperature of the aqueous body, temperature of the atmosphere above the aqueous body and the movement of the atmosphere or the aqueous body. The amount of the alkylmethylsilane is usually applied to provide at least a monomolecular layer on the aqueous surface. However, more or less can be used depending upon the desired result. If one desires to control the rate of evaporation, one can apply less of the alkylmethylsilane to provide some specific rate of evaporation which can be used as a means of controlling the temperature of an aqueous body.

The aqueous body can be a swamp, a field covered with water, a pond, a lake, a reservoir, or in a tank, in a ditch, in a dish, in a closed container with a controlled atmosphere and the like.

The alkylmethylsilanes can be applied to the aqueous body as is or in the form of an organic solution or by any other means suitable to disperse the compound over the aqueous surface.

The alkylmethylsilanes of the present invention retard the evaporation of water.

The following examples are illustrative only and should not be construed as limiting the invention which is properly delineated in the appended claims.

EXAMPLE 1 A mixture of 9.5 g. of I-I (CH SiCl and 25.3 g. of octadecene-l was placed in a bottle and 3 drops of a one weight percent platinum as chloroplatinic acid in isopropanol was added. The resulting mixture was placed in a C. oven overnight and then allowed to stand for two weeks. The mixture was then distilled and 01511378 iCl was obtained.

A solution of 2.07 g. of the octadecyldimethylchlorosilane in tetrahydrofuran was prepared. To a mixture of 0.65 g. of LiAlH, in tetrahydrofuran, the octadecyldimethylchlorosilane was added. After the evolution of gas stopped, the mixture was filtered and the filtrate was allowed to stand over the weekend in hood to evaporate the solvent. The product was EXAMPLE 2 Mixed 11.5 g. of H(CH )SiC1 23.3 g. of octadecene- 1, and 2 drops of one weight percent platinum as chloroplatinic acid in isopropanol in a two ounce bottle. The

bottle was capped and placed in a 110 C. oven overnight. The resulting mixture was distilled and was The results below are the weight percentages of water lost in a given period of time under the test conditions.

l Percent C1s a7 SiOlz Percent water loss after savings Dissolved 3.5 g. Of the octadecylethyldichlorosilane in Compound lday 2 days 5 days 7days corit i' l tetrahydrofuran. Added 0.2 g. of LiAlH to tetrahydro- 1 C 1 7 3 14 7 35 0 47 2 furan and then added the octadecylmethyldichlorosilane O on u I solution to it. After the evolution of gas stopped, the E mixture was filtered and the solvent evaporated from the (2) CisHsrSiHz 4. 0 7.5 10. 0 20. 0 44. 9 filtrate. The product was a white solid of the formula 10 (CHM (13113 a) C1aH3 iH 4.5 0.5 10.5 31.5 33.3 Cis avsiHz (C1192 EXAMPLE 3 l5 4 cinngsnr 4.5 10.0 15.0 25.5 40.0 A mixture of 19.6 g. of tetradecene-l, 9.4 g.

EXAMPLE 5 H(CH3)2S1C1 When the following olefins are reacted with the desigand 3 drops of a solution of one weight percent platinum nated methylchlorosilane by the process described in as chloroplatinic acid in isopropanol was placed in a Example 2, the products as shown in the following table small bottle and then allowed to stand in a 120 C. oven are obtained.

Olefin Silane Product (CHM CH =CH(CH )nCH3 H(CH SiC1 CH 'CHmsnI (1111 CH =CH(CH.)1 OH.. H(CH )SlClz CHnoIImstHz (IIIIQ, CHz=Cl1(CH2) CH ..H(CH. siC1 crmommstm (CHM ClI =CH(CH2)tzCH; .lI(CI-l'. SlCl CH (CI-Iz)nSiH 0 CHFCHCHKCHQWCHQL men. S101 {CH3(CII2)10]2CII(CHzhsll lg (CHM CHz=CH(CH CI-l H(CH SiCl CHMCHzMSiH overnight. The resulting mixture was distilled and the That which is claimed is: product collected was 1. An alkylmethylsilane of the formula 92 C14H20SlCl (9H0); To a mixture of 0.2 g. of LiAlH in tetrahydrofuran, (CY-H10) 51110) 5.8 g. of the tetradecyldimethylchlorosilane in tetradrofuran was added. After the evolution of gas stopped in which n is an integer of from 12 to 45 inclusive and x the mixture was filtered and the tetradrofuran was evapois an integer of from 1 to 2 inclusive. rated, leaving 2. The alkylmethylsilane in accordance with claim 1 (Cum wherein n is 18 and x is l. C H 3. The alkylmethylsilane in accordance with claim 1 wherein n is 18 and x is 2. as the Product. 4. The alkylmethylsilane in accordance with claim 1 EXAMPLE 4 wherein n is 14 and x is 2. Ten weight percent solutions of monooctadecyldif d methylsilane in diethyl ether, monooctadecylmonomethyl- Re erenccs silane in diethyl ether and monotetradecyldimethylsilane UNITED STATES PATENTS in diethyl ether were prepared. Ten drops of each of 2,129,281 9/1938 Lincoln at 260 448 2X these three ether solutions were placed on the surface 3,291,760 12/1966 Bayer 443 2 of 100 g. of tap water in a 250 ml. stainless steel cup. The resulting assembly was placed in a controlled atmos- TOBIAS LEVOW, p i Examiner phere of relative humidity at 68 F. The weight 65 of the cup, water and ether solution was initially made and then observed at time intervals of 1 day, 2 days, 5 days and 7 days. A control cup was also placed in the controlled atmosphere. The control was prepared as above but without any silane solution.

P. E. SHAVER, Assistant Examiner US. Cl. X.R. 260448.2R 

